A multi-home network device is a device that is simultaneously physically connected to multiple networks through multiple network interfaces such as Ethernet, Wi-Fi, Bluetooth, USB, to name a few. Examples of multi-home network devices may include, but are not limited to, network routers, bridges, switches, personal computers, laptop computers, tablets, mobile phones, and automotive infotainment units. It is possible for multi-homed devices to provide connection to the Internet through more than one of its network interfaces. For example purposes only, the description herein refers to an automotive infotainment device having Wi-Fi and Ethernet network interfaces. The infotainment device is capable of connecting to the Internet by way of two routes. By way of the Wi-Fi interface, the infotainment device may connect to an access point, such as a public, home, or office W-Fi hotspot which may connect to the Internet. By way of the Ethernet interface, the infotainment device may connect to a telematics unit on the vehicle having a modem (3G/4G) which may connect to the Internet.
While the infotainment device is capable of connecting to the Internet by way of multiple devices simultaneously, in practice, it is connected to the Internet through only one device at a time. This is due to the fact that it is standard practice for a network routing table of any network device to have a single “default” route entry, which defines the route to an Internet gateway.
There is a need for a method to detect which network interface should be used as a “default” gateway to connect a device to the Internet when multiple network interfaces are available and to offer uninterrupted Internet connectivity (high availability) when the “default” Internet gateway interface either becomes unavailable or the internet from the current default gateway goes down.